In general, electric power is generated by hydraulic power generation, steam power generation or atomic power generation. These power generation methods often pose problems of air pollution, ozone layer destruction and water pollution.
In an effort to develop clean energy or alternative energy, scientists over the world have been studying power generation methods that make use of solar heat, wind power and tidal power. Also developed is a power generation method that utilizes water flowing along a river.
The power generation methods using solar heat, wind power, tidal power and river flowing water are advantageous in that they do not contaminate environments and can generate electric power relying upon natural energy. Moreover, such power generation methods assist in saving fossil fuels and underground resources which have been extensively used to generate electric energy.
However, the power generation methods using natural energy suffer from the following drawbacks.
A solar generation device mainly installed in buildings or houses is bulky and costly to install. In case of bad weather, the solar generation device is hard to generate electric power. These shortcomings make it difficult to supply electric power in a stable manner. In other words, the power generation methods using natural energy such as solar heat, wind power, tidal power and river flowing water are heavily affected by weather conditions.
Korean Patent No. 10-0780316 discloses a hydraulic power generation device that uses, as its drive power source, the hydraulic energy of the drinking water, agricultural water or industrial water flowing out from a building water tank, a water purification facility or a reservoir.
The hydraulic power generation device cited above is designed to generate electric power using the kinetic energy of flowing water supplied from a water source such as a dam, a river or a reservoir to a water collection tower or a water tank installed in a school, a building or a factory.
In the hydraulic power generation device, the energy of flowing water acts on vanes and rotates a rotor. The torque generated at this time is transferred to a generator so that the generator can be rotationally driven to generate electric power.
However, the vanes employed in the hydraulic power generation device suffer from a number of problems, including the noise caused by the wear of vane hinges, the premature wear of the vanes occurring due to the sliding contact of the vanes with the inner surface of a casing, the noise generated when the vanes are unfolded into contact with the support claws of the rotor and the water leakage through the gaps around the vanes. In addition, the rotor having the support claws is difficult to manufacture and the number of fabrication steps of the rotor are increased. Since the vanes are arranged inside the casing in a foldable manner, the casing has a complex structure and involves a difficulty in the manufacture thereof. This leads to reduced productivity. The inlet and outlet ports arranged at the opposite sides of the casing make the device quite complicated.